There are various communication apparatuses that are configured to perform non-contact communication with external devices. By using non-contact communication, for example, it is possible to access to a memory in a communication apparatus from an external device for reading or writing data, and to instruct a communication apparatus to perform a function from an external device. For example, NFC (Near Field Communication) is known as a non-contact communication method.
In these communication apparatuses, it is convenient if non-contact communication with an external device can be performed as necessary to access the memory and to instruct execution of a function, even in a state where power is turned off or a power plug is pulled out and hence a normal operation is stopped.
Technology is known that power is fed from an external device to a terminal device on which a battery is not mounted, by non-contact power feeding, so that the terminal device is started up as usual by the fed electric power for performing necessary processes.